An individual who does not conform to the thoughts, or beliefs of others. They tend to be considered very strange, but in reality, are more accomplished than many that follow the normal.
john lennon was an eccentric person in the genere of music he choose to preform during his time.
another example could be marilyn monroe.
Someone who is considered crazy or insane; someone who does not conform to society's norms.
Designating someone 'eccentric' versus 'crazy' depends on how much money they have. Eccentric behaviour is usually made possible by large amounts of money.
Person 1: Dude, that guy's crazy!
Person 2: Are you kidding me? Have you seen his mansion?? Guy's eccentric.
Person 1: Oh, well in that case.
Sir Appleton, as he now wishes to be called, planted a hundred apple trees which he now protects 24/7 with a full squadron of men dressed as the Queen's Guards. What an eccentric guy!
A: Did you hear what that guy did? He's stealing scabs and kicking midgets! He's fucking nuts!
B: Nah, he's rich, so we call it eccentric.
A: Oh, he's got money? Then it's fine, nevermind.
B: Kicking midgets is always fine.